<p>todolist works!</p>
<input type="text" [(ngModel)]="username" (keyup)="addusername($event)" >
<button (click)="getusername()" >增加</button>
<!--通过双向数据绑定获取新的值-->
<button (click)="addusername($event)">add list</button>
<ul>
  <li *ngFor="let item of list;let i=index">
    <input type="checkbox">
    {{i}}---{{item}}
    <button (click)="deleteItem(i)" >删除</button>
  </li>
</ul>

<h2>正在进行</h2>

<h2>已经完成</h2>
